1. Technical Field
The present invention relates to liquid containers that store liquid to be supplied to liquid ejecting apparatuses.
2. Related Art
Examples of liquid containers to be mounted in liquid ejecting apparatuses include ink cartridges to be mounted in ink jet printers. In particular, ink cartridges having ink sensors that detect the amount of ink stored therein are practically in use. In general, an ink sensor detects whether or not ink is present in a sensor chamber communicating with an ink storage section. Specifically, the ink sensor detects the presence/absence of ink on the basis of physical properties of ink, or liquid, and air: for example, the difference in vibration frequency specific to a system including the sensor chamber, and the difference in refractive index of light passing through the sensor chamber. This leads to a problem that, if bubbles are contained in the ink in the sensor chamber, detection accuracy may be deteriorated. To solve this problem, JP-A-2006-248201 discloses an exemplary technique in which a bubble-trapping section is provided between the sensor chamber and the ink storage section, whereby entry of bubbles into the sensor chamber is suppressed.
However, in the known technique in which the bubble-trapping section is constituted by a flow path exposed at and extending parallel to the bottom surface of the ink cartridge and a covering member covering the flow path airtight, most of the flow path is covered with the covering member, which has a flexibility. This leads to some problems in that the pressure inside the flow path changes frequently, resulting in insufficient bubble-capturing capability, and that the flow path needs to be covered airtight with the covering member dedicated thereto, resulting in increase in the number of manufacturing steps and the manufacturing cost. In addition, depending on the orientation of the ink cartridge, entry of bubbles into the sensor chamber cannot be suppressed sufficiently.
The foregoing problems do not only apply to ink cartridges but are common to various liquid containers that are used for supplying liquid to liquid ejecting apparatuses, such as liquid containers that supply liquid materials containing metal to ejection apparatuses that eject the liquid materials onto semiconductors so as to form electrode layers.